Wagner’s decision, first reported by the Washington Examiner on Monday, was a surprise to operatives watching the race, since the third-term congresswoman had been signaling that she would challenge McCaskill.

So how will how her decision not to run affect the developing GOP primary? It depends who you ask.

“We were facing, before today, a decent possibility, maybe a 50-50 possibility, of an expensive primary fight,” Gregg Keller, a GOP strategist, said Monday. “After today, I think the chances of that are lesser and therefore Republicans are in a better spot.”

Roy Temple, a former chairman of the Missouri Democratic Party, had a different take.

“There is a conversation every two years about how the Republican establishment is going to pick their favorite politician,” he said. “That is always harder to do than it is to talk about doing.”

Temple pointed to people such as GOP Rep. Vicky Hartzler who could still run for the Senate. Eric Schmitt, the state treasurer, is also believed to be a potential contender.

A new face

But many eyes in the Show Me State now turn to Hawley, who won his attorney general race last fall by 17 points, as Republicans swept all statewide offices. The 37-year-old garnered around 13,000 more votes than President Donald Trump, who won the state by nearly 19 points.

So far Hawley has not indicated whether he will run. He told the St. Louis Post-Dispatch last month that he was focused on his current job and it was “awfully early” to be talking about other elections. But he also did not explicitly rule out a Senate run.

“Just six months into his new job, Josh Hawley is already looking for the next campaign,” Missouri Democratic Party Chairman Stephen Webber said in a statement. “It seems he’s more busy looking up the ladder, than looking out for Missouri.”

Former Missouri Sen. Jack C. Danforth said Hawley could afford to delay his announcement since he will likely not have a problem raising money should he decide to challenge McCaskill. Danforth has been encouraging the attorney general to run.

A family decision

But it does not appear that Fox’s missive affected Wagner’s decision to forgo a Senate run. Instead, her decision was based on the importance of her family, which is her top priority, a campaign source said.

In a statement Monday, Wagner said the 2nd District is her home and “there is no greater honor than representing a place and people that I love.”

Wagner is also a strong fundraiser in her own right, and sits on the powerful (and lucrative) House Financial Services Committee. She raised more than $800,000 in the first three months of 2017, and had nearly $2.8 million in cash on hand, according to Federal Election Commission records.

The filing period for the second fundraising quarter ended June 30. The Wagner campaign source said her team had a similar fundraising haul to the first quarter.

Democrats jumped on Wagner’s announcement as an indication that Republicans face a broader recruitment problem as the GOP-controlled Congress tries to advance their health care legislation that is proving unpopular.

“It’s no surprise potential Republican Senate candidates are refusing to run under their party’s toxic health care plan. … [T]he GOP brand is in tatters and their candidates have nothing to run on except a string of broken promises,” said David Bergstein, a spokesman for the Democratic Senatorial Campaign Committee.

Avoiding a 2012 repeat

But Keller, the GOP operative, said Wagner’s decision is “bad news for Democrats” because it lowers the likelihood of a crowded — and expensive — Republican primary. Missouri Republicans are hoping to avoid that scenario which played out during McCaskill’s previous run for re-election.

“Everyone has been focused on avoiding a Todd-Akin style debacle here,” Keller said.

Keller said for McCaskill to win again next year, three “dominoes” would have to fall: a nasty GOP primary, a candidate like Akin who makes unforced errors, and a sharp drop in Trump’s approval ratings in Missouri (he is still relatively popular in the state).

“Following today, I believe the chances of those three dominoes falling got narrower,” Keller said.

But Democrats point to McCaskill’s work ethic on the campaign trail and the Senate, and say she will be tough to beat. Inside Elections with Nathan L. Gonzales rates this race a Toss-up.